A cheap pill developed to treat Alzheimer’s disease could reverse brain damage caused by teenage binge drinking, according to new research.
Aricept, known medically as donepezil, costs just 6p a day. It is taken by tens of thousands of British adults with mild to moderate dementia to slow mental decline.
In experiments, it reversed learning and memory problems in adult rats that had been exposed to large quantities of alcohol during adolescence.
Their mental skills were boosted – after just four days of treatment with the cognition boosting medication.
Booze is more likely to destroy neurons in youngsters than older peers because their grey matter is still developing.
Study senior author Professor Scott Swartzwelder said: “Research has begun to show human adolescents who drink early and consistently across the adolescent years have some deficits in brain function that can affect learning and memory, as well as anxiety and social behaviours.
“The changes can be subtle, but who wants even subtle deficits in their brain function or how they think and feel?
“Studies in animal models show adolescent alcohol exposure can change the ways nerve cells communicate with each other, and the level of plasticity in brain circuits – compromising the ability of the brain to change and adapt.
“These changes can be seen in adulthood – long after the alcohol exposure has ended.”
It would be unethical to get teenagers to drink, but developing rat brains can mimic the effects caused by alcohol.
The US team achieved this through “intermittent exposure”. This led to blood alcohol levels mirroring those of teens and young adults who binge drink a few times a week.
It changed the hippocampus – an area critical for learning and memory, and also linked to anxiety. There was inflammation and fewer neurons were being born.
The groundbreaking study also suggested neurons were dying faster – making it easier to shed existing ones and harder to replace them.
Once they reached adulthood, some of the lab rodents were given donepezil. Scans showed less inflammation and more new brain cells compared to rats not receiving it.
Prof Swartzwelder, a psychiatrist at Duke University in the US, said: “We don’t know if the reversal of these alcohol effects by donepezil is permanent, but it at least transiently reverses them.”
The findings, published in the journal Scientific Reports, helps clarify the subtle health risk of heavy drinking among young adults, which has been difficult to ascertain.
Prof Swartzwelder said: “It is obvious not everyone who drinks during adolescence grows up and completely fails at life.
“You might not notice the deficits in obvious ways every day, but you run the risk of losing your edge.
“Sometimes a small impairment of brain function can have a broad ripple effect in someone’s life.”
Importantly, the research demonstrates the potential to repair some types of damage caused by adolescent alcohol exposure, he said.
But beyond that, it could also lead to a more specific understanding of the cellular mechanisms that make the developing brain particularly vulnerable to substances such as alcohol.
Four years ago a study found dementia patients taking donepezil were twice as likely to still be in their home a year later, instead of care.
Costing just £21.59 a year, most doctors withdraw it in advanced stages of the disease because of a lack of evidence that it helps.
But keeping patients on the drug could help them avoid being placed in a nursing home, said the University College London team.
Donepezil boosts the levels of communication chemicals within the brain. It slows the decline of memory as well as the ability to carry out everyday tasks.
Among patients with advanced dementia, the effect is only modest. But the research showed even a slight brake on cognitive decline was enough to significantly delay admission to a nursing home.
In February this year a US study reported binge drinking makes teenagers depressed and prone to alcohol-use disorders in later life.
It found overindulging in alcohol as a teen alters the expression of the protein BDNF, which controls fear and anxiety in grey matter.
And last year experiments on mice found binge drinking during your teenage years interferes with the developing brain – leading to poor memory in adulthood.
It damaged the lab rodents’ pre frontal cortex, which is also crucial to planning and making complex decisions.
